[PATCH] Staging: comedi: Add DMA preparation before mite_dma_arm().

[Wentao Liang]

The ni_tio_input_inttrig() calls mite_dma_arm() without calling
mite_prep_dma() first. A proper implementation can be found in
ni_cdo_inttrig() in ni_mio_common.c.

Add mite_prep_dma() before mite_dma_arm().

Fixes: cb7859a90af1 ("Staging: comedi: add National Instruments infrastructure")
Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>
---
 drivers/comedi/drivers/ni_tiocmd.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/comedi/drivers/ni_tiocmd.c b/drivers/comedi/drivers/ni_tiocmd.c
index ab6d9e8269f3..b943836ccf1a 100644
--- a/drivers/comedi/drivers/ni_tiocmd.c
+++ b/drivers/comedi/drivers/ni_tiocmd.c
@@ -84,9 +84,10 @@ static int ni_tio_input_inttrig(struct comedi_device *dev,
 		return -EINVAL;
 
 	spin_lock_irqsave(&counter->lock, flags);
-	if (counter->mite_chan)
+	if (counter->mite_chan) {
+		mite_prep_dma(counter->mite_chan, 32, 32);
 		mite_dma_arm(counter->mite_chan);
-	else
+	} else
 		ret = -EIO;
 	spin_unlock_irqrestore(&counter->lock, flags);
 	if (ret < 0)
-- 
2.42.0.windows.2